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Gravity - Alternate Explanation

My possible explanation for gravity:

Gravity is caused by the expansion of space imparting a force on matter. Space naturally expands; even the space contained within a massive body such as Earth or an atom is expanding. When the space attempts to expand into the area occupied by matter, it is unable to do so but I believe it imparts a force on that matter that we call gravity. If this is true it would negate the necessity for gravitons or gravity waves which, for which IIRC no direct evidence has been found.

I also think that space would resist its own expansion so that the force of gravity would actually be related to the amount of space in any massive body. Imagine the Earth compared to a black hole. There is no space in a black hole (or very little) while there is a lot of space in the Earth in between molecules and within atoms, etc. Therefore a black hole's gravity is near the maximum possible gravity possible in our universe (no space [edited] is present.)

I'm no mathematician or formally educated scientist but I am familiar with the properties of the universe and most physics and logically, it seems that all the formulas currently in place for gravity would still be valid. Gravity would depend on what I call "spacial density" as opposed to the amount of matter but it would still work similarly if not exactly the same as what we observe now.

I am curious, mathematics-wise, how this would work on a galactic scale with the issues relating to spiral galaxies that only the existence of dark matter can resolve (i.e. spiral galaxies are spinning too fast to maintain their shape unless dark matter exists.)

I would very much like to hear other opinions and comments about this alternate idea for gravity.

Just a reminder that the ATM forum is not intended as a collaborative or developmental environment in which to speculate, spitball, or solicit opinions. The most likely form of feedback will be challenging questions and critiques about the presented theory. Have fun.

There is an idea out there called push gravity. Tom Van Flandern promoted it. It proposes that we are being push at on all sides by gravity and that mass actually blocks the push from a direction and this pushes objects together. It's interesting.

Why would expanding space impart a force on matter? And how would that cause it to manifest the way we see it manifest (i.e. a pull toward the centre of the mass)

I apologize for not being clearer on my first post. This is the first time I have posted on here or any site about my ideas on cosmology. I was attempting to "get the conversation started."

All space is forever expanding. As long as no matter is present then there is no interruption to this expansion. However, if matter is present, space cannot expand into the area occupied by that matter so does it just leave the matter alone? I was thought-investigating what it would look like if instead of just ignoring the presence of matter when it expands, what if spatial expansion actually imparted a force on the matter it interacts with, if it interacts with it at all.

If you look at the planet Earth and the gravity associated with it, could it be that spatial expansion is actually squeezing everything together through this imparted force and, therefore, the planet would seem to be attracting objects to it when in reality the planet and the object (man, car, the moon, etc.) are being squeezed together by spatial expansion.

Initially I discounted the idea thinking that long ago everything would have been squeezed together into one or more gigantic balls of matter. However, when you consider that the space on the interior of the planet is also expanding and is possibly partially counteracting the expansion force outside the planet squeezing everything together, what you have left is the difference between the force of expanding space outside the planet and the expanding space inside the planet (or a net force directed toward the center of the planet). We would know this difference in forces as gravity.

There are other considerations and this is just the basic explanation. For example, since space by its nature expands in every direction at the same time, spatial expansion is omni-directional. This goes for the space on the interior of the planet as well so not all of it could be said to be counteracting external expansion forces and, with my limited abilities, the math seems somewhat daunting. Also, since the nature of spatial expansion is omni-directional, any volume of space that is considered must be a perfect sphere. When you consider the gravity of the planet Earth, you must actually consider the smallest perfect sphere that the planet could fit into and then compare it to an equivalent volume of space outside that sphere to come up with a difference in the amount of space present (total volume of space for each less the amount of matter present in each), and, therefore, a net force squeezing everything toward the center of the sphere would result. In this case this would be the center of the sphere or planet.

Something I am working on in my limited capacity is re-creating gravitational formulas by replacing the mass items with spatial density items. For example, a black hole or singularity would have a spatial density of zero or near-zero while a planet like Earth would have a spatial density much closer to 100%. I know from looking it up that the Earth's mass is 5.9722 x 10-24 kilograms. However, there is space in atoms as well and I am not well-versed in chemistry so I don't know if the planet's mass includes this or not. How do we include all of the space (in between molecules as well as inside of atoms or the atom's nucleus in the total? Once that is included you will come up with a difference in the amount of space or matter actually present in 2 equal volumes of space. In every case, the net force would be toward the volume with the lowest spatial density (or highest amount of matter). It is almost like accepting gravity as it is currently understood but reversing the mechanism that causes it. Logically, I think the math will work out the same but since I have not [added 'not'] calculated the quantities, it is just a guess right now.

I know this is kind of "out there" but I don't see how any of this violates known observations about gravity and it also includes spatial expansion to come up with an explanation. Another aspect of this idea is that it eliminates the need for gravitons or a gravity field to explain gravity, neither of which, if I recall correctly, have been directly observed. Spatial expansion (or its effects) has been directly observed in the far-distant galaxies that are receding from us at an ever-increasing speed the further they are away from us. Also, per Occam's Razor, with all things being equal, the simplest answer (fewest assumptions) tends to be the correct one. Unless there is some observational or experimental evidence that shows why this cannot be true then it is potentially a much simpler explanation for gravity than believing in a magical force emanating from matter that draws other matter to it and which no part of its fundamentals has ever been observed. Also, gravity is the only centripetal force known in nature, IIRC, and that makes me extremely skeptical of its validity.

Thank you very much for your post and I anticipate further discussion.

There is an idea out there called push gravity. Tom Van Flandern promoted it. It proposes that we are being push at on all sides by gravity and that mass actually blocks the push from a direction and this pushes objects together. It's interesting.

Very, very interesting. I haven't heard of push gravity before but it sounds very similar. I will look into it. In the meantime if you want to refer to my response to DaveC426913's post, I would love to hear your comments.

Space only expands where there is a uniform distribution of matter. This is not the case around the Earth, or even the solar system.

Also, the expansion of space is a consequence of GR. And GR also explains gravity. So it seems rather odd to try and use part of GR to come up with an explanation for something already explained by GR.

There is an idea out there called push gravity. Tom Van Flandern promoted it. It proposes that we are being push at on all sides by gravity and that mass actually blocks the push from a direction and this pushes objects together. It's interesting.

Originally Posted by MikusF318

Very, very interesting. I haven't heard of push gravity before but it sounds very similar. I will look into it. In the meantime if you want to refer to my response to DaveC426913's post, I would love to hear your comments.

Folks, I provided what I thought was a pretty clear warning that this thread is not a collaborative, anything-goes environment. This thread has one topic and one proponent. Do not introduce or discuss competing ATM theories or other sidetracks.

Space only expands where there is a uniform distribution of matter. This is not the case around the Earth, or even the solar system.

Also, the expansion of space is a consequence of GR. And GR also explains gravity. So it seems rather odd to try and use part of GR to come up with an explanation for something already explained by GR.

Is the "uniform distribution of matter" comment limiting where space expands part of GR? I have not heard that and would like to research it further.

Also, I had expansion of space being a consequence of Hubble's work showing that all space in every direction was expanding forcing the matter beyond to accelerate away from us observers at an ever-increasing rate. I have never head of expanding space being associated with GR. Please give me a little to go on with that comment as well so that I can investigate.

Thank you for the information. That is why I posted on here in the first place.

Is the "uniform distribution of matter" comment limiting where space expands part of GR? I have not heard that and would like to research it further.

It is worth starting from first princi- ples and asking what the general relativistic picture of cosmology actually contains. The adoption of the cosmological principle, in that the Universe is homoge- neous and isotropic, restricts the form of the underly- ing geometry of the Universe, expressed in terms of the FRW metric. With this metric, the continuity equa- tion demonstrates that in other than finely-tuned or contrived examples, the density and pressures of cos- mological fluids must change over cosmic time, and it is this change that represents the basic property of an expanding (or contracting) universe.

Also, I had expansion of space being a consequence of Hubble's work showing that all space in every direction was expanding forcing the matter beyond to accelerate away from us observers at an ever-increasing rate. I have never head of expanding space being associated with GR. Please give me a little to go on with that comment as well so that I can investigate.

There is a good, brief, summary of the history of the idea here: http://forum.cosmoquest.org/showthre...e-Lemaitre-law (with a link to a paper with more detail).
Note that theory came first, then initial evidence (from Lemaitre and Hubble) then further evidence (CMB, etc)

Space only expands where there is a uniform distribution of matter. This is not the case around the Earth, or even the solar system.

Also, the expansion of space is a consequence of GR. And GR also explains gravity. So it seems rather odd to try and use part of GR to come up with an explanation for something already explained by GR.

A couple of other comments, Strange, and I have to go home from work, but I wanted to thank you for your time responding to my posts.

My first comment would be that, in my opinion, any new theory that covers an unexplained cosmological or physical condition or attribute would necessarily contain some elements of previously existing work that was also based on observed events. That just seems logical to me. However, since it is a new idea, then it necessarily would not contain ALL of the ideas in the previously existing work. So if my idea does contain portions of GR but does not accept all of the descriptions/predictions of GR, it seems like that would logically be the case.

Second, if you are referring to the relationship between space and time (space-time) proposed by GR as the explanation by GR for gravity, I propose that it should actually be referred to as "spatial expansion-time" instead of "space-time." Not to take anything away from the massive genius that was Sir Einstein, but I do not believe he was ever aware of the importance of expansion in the cosmos. That is just my opinion and I look forward to further comments hereon.

There is a good, brief, summary of the history of the idea here: http://forum.cosmoquest.org/showthre...e-Lemaitre-law (with a link to a paper with more detail).
Note that theory came first, then initial evidence (from Lemaitre and Hubble) then further evidence (CMB, etc)

Then I suspect this thread will soon be closed.

So I have been going over these documents to see how they relate to my ideas on this issue. I have the following points to make regarding the sources to which you refer.

The first document, "Expanding Space - The Root of All Evil" seems to be a treatise on the dangers of using the idea/phrase/terminology of "expanding space" when dealing with established mainstream science theories such as GR. Even so, in the section on dark energy it is argued that using the FRW metric in a universe that is dominated by an homogenous energy (as we believe ours is) "...the expansion rate will apply equally on all scales." It goes on to state that "...However, so long as the equation of state w of the dark energy obeys the condition w ≥ −1 the energy density will not increase with time and bound structures will remain bound and stable."

The next document, a wiki article describing the FLRW metric very clearly states that it "... starts with the assumption of homogeneity and isotropy of space." This very clearly isn't the case in the "lumpy" universe in which we reside.

Regarding Einstein's awareness of expansion, I agree, he was aware of it. However, he did his best to discredit the idea with his cosmological constant to cancel the effects of gravity, an idea he himself called the worst mistake of his career. So again, I believe that he never understood the "importance" of spatial expansion in our cosmos.

All of these ideas are mathematical constructs and/or theories based on mathematical formulations attempting to describe our universe and, for the most part, are accepted as true and correct. I also believe that they are "mostly" true and correct as is anything that seems to accurately predict observations. However, this is an alternate theory forum, and I believe even with all of the theoretical documentation you provided (which I sincerely appreciate), nothing in what I have read would invalidate any of my ideas above.

Obviously I will keep researching this advanced level of cosmological theory as I am not currently familiar with all of it, but would also like to keep getting constructive criticism on my ideas.

Scott Adams, the Dilbert cartoonist, proposed this in one of his books years ago.

I'm not sure if that would be considered a competing ATM theory by the moderators so I am reluctant to comment on it. I've already been chastised for not following rules and don't want it to continue to happen.

So I have been going over these documents to see how they relate to my ideas on this issue. I have the following points to make regarding the sources to which you refer.

The first document, "Expanding Space - The Root of All Evil" seems to be a treatise on the dangers of using the idea/phrase/terminology of "expanding space" when dealing with established mainstream science theories such as GR. Even so, in the section on dark energy it is argued that using the FRW metric in a universe that is dominated by an homogenous energy (as we believe ours is) "...the expansion rate will apply equally on all scales." It goes on to state that "...However, so long as the equation of state w of the dark energy obeys the condition w ≥ −1 the energy density will not increase with time and bound structures will remain bound and stable."

The next document, a wiki article describing the FLRW metric very clearly states that it "... starts with the assumption of homogeneity and isotropy of space." This very clearly isn't the case in the "lumpy" universe in which we reside.

In both cases, the answer is that the universe is (and always has been) homogeneous on large scales. So expansion occurs on large scales. Expansion does not occur locally because, as you say, locally it is "lumpy". Another way of describing this, that is often used, is to say that structures from the solar system up to galaxy clusters are held together by gravity.

Also, the same theory that predicted and explains expansion also explains gravity. So it doesn't make much sense to try and use one part of this theory to undermine another part of it.

Regarding Einstein's awareness of expansion, I agree, he was aware of it. However, he did his best to discredit the idea with his cosmological constant to cancel the effects of gravity, an idea he himself called the worst mistake of his career. So again, I believe that he never understood the "importance" of spatial expansion in our cosmos.

Why would he describe it as his worst mistake if he didn't appreciate how important it was.

All of these ideas are mathematical constructs and/or theories based on mathematical formulations attempting to describe our universe and, for the most part, are accepted as true and correct.

With the caveat that "true" is a rather contentious term, that is pretty much what science does.

I also believe that they are "mostly" true and correct as is anything that seems to accurately predict observations.

"Mostly" would imply there is some area where there is a disagreement between theory and what we observe. So far, there isn't.

So your use of the word "mostly" is not based on any evidence. In other words, not science.

In both cases, the answer is that the universe is (and always has been) homogeneous on large scales.

Not sure I agree with this statement. The largest scale we can deduce at this point is the cosmic web showing the filaments that are connecting galaxy clusters, superclusters, etc. This is definitely not homogenous. In any event, I believe it is a moot point since in our universe which mainstream science agrees is homogenous with respect to dark energy, expansion is the same on all scales and according to the currently observed conditions in the universe, the second condition is also met so that local, stable objects will remain stable. Basically, my idea replaces dark energy with spatial expansion. Like my ideas on gravity, spatial expansion is another facet of my on-going attempt to create a "logical" unifying theory. I can't really get into that much more without getting the moderators on my back about having multiple ATM ideas on a single forum. Maybe once this thread is closed I will create a new thread to discuss dark energy and dark matter and why spatial expansion can explain both.

Originally Posted by Strange

Also, the same theory that predicted and explains expansion also explains gravity. So it doesn't make much sense to try and use one part of this theory to undermine another part of it.

As I said earlier, doesn't it make sense that any new theory that works will necessarily include portions of prior theories that also work? They will all be trying to explain observational facets of the universe and if the prior theory [Edited to replace 'quote' with 'theory'] was completely wrong, it couldn't predict observations. GR does very definitely predict observations so, logically, at least part of it must be correct.

Originally Posted by Strange

Why would he describe it as his worst mistake if he didn't appreciate how important it was.

I think you misunderstood what I was saying. Einstein created his cosmological constant in an attempt to do away with expansion all together. He was forcing his theory to describe a steady-state universe. Once he finally conceded that, yes, the universe was expanding, he retracted his cosmological constant idea, which re-introduced expansion into his calculations and theory. His "greatest mistake" was trying to force expansion out of his theories with the use of the cosmological constant. In the end, expansion was a part of his theory as it is today but that does not mean he understood the importance of it. Most people today, I believe, fail to understand the importance of expansion especially if there is any merit to my ideas on the subject. Keep in mind, that statement was a personal opinion of mine and, therefore, I am perfectly fine agreeing to disagree about it.

Originally Posted by Strange

"Mostly" would imply there is some area where there is a disagreement between theory and what we observe. So far, there isn't.

So your use of the word "mostly" is not based on any evidence. In other words, not science.

Sorry but I have to strongly disagree with this statement. There are multitudes of ideas and physical observations which are "mysteries" because we don't really understand how they work, but we still have theories covering them. Yes, GR predicts gravity but also, in order to be true we need to detect gravitons or a gravity field which controls gravity. Thus far we haven't so I feel completely justified in saying that GR is mostly true at this point. My ideas above also predict the effects we know as gravity so does that make it true? No, in fact I wouldn't even say it is partially true at this early stage of criticism. Dark energy, dark matter, the asymmetry of matter-antimatter ratio in our universe, et al, are some other ideas for which we have theory but no proof of being completely correct. I believe we can say the entire field of physics and cosmology, or GR and QM together, is mostly true at this point because they do not explain "everything" in the field.

I would very much like to hear other opinions and comments about this alternate idea for gravity.

Hi, MikusF318.
The idea is too vague to be an alternative for the mainstream theory of gravity (general relativity). An idea that can predict anything is as invalid as an idea that has invalid predictions.

There are some slight misconceptions about the history of GR. Einstein introduced the cosmological constant to allow the possibility of a static universe because that was the prevailing theory. He was forcing solutions of his theory to have an expanding, contracting or static universe. Along came good evidence that the universe was expanding. Everyone put the cosmological constant to 0, i.e. it was not "retracted". The 1998 discovery of dark energy was basically astronomers testing whether setting the cosmological constant to 0 was correct.

I know this is kind of "out there" but I don't see how any of this violates known observations about gravity and it also includes spatial expansion to come up with an explanation.

So far, we don't have enough details to even determine whether or not it violates known observations.

Another aspect of this idea is that it eliminates the need for gravitons or a gravity field to explain gravity, neither of which, if I recall correctly, have been directly observed. Spatial expansion (or its effects) has been directly observed in the far-distant galaxies that are receding from us at an ever-increasing speed the further they are away from us. Also, per Occam's Razor, with all things being equal, the simplest answer (fewest assumptions) tends to be the correct one. Unless there is some observational or experimental evidence that shows why this cannot be true then it is potentially a much simpler explanation for gravity than believing in a magical force emanating from matter that draws other matter to it and which no part of its fundamentals has ever been observed.

Instead, you've replaced it with space "magically" pushing matter ... how does it do that?

Also, gravity is the only centripetal force known in nature, IIRC, and that makes me extremely skeptical of its validity.

What do you mean by that? Electromagnetism behaves similarly, doesn't it? What characteristic of gravity makes it "centripetal", and electromagnetism not?